Upgrade with SSWU than downgrading back to Y on another day (and then try SSWU again)
 

The scenario is that a passenger upgrades to J with a SSWU for a Tango Plus fare via IKK or was waitlisted and was upgraded the day before departure. Flight plans change, can the passenger call AC and pay the change fee/class of service difference and get back to Y for another day? Moreover, then call in and upgrade to J within the 4 day window or waitlist for upgrade on that future flight?

I can't imagine why this wouldn't be legal, I just wanted to see if there was any practical experience regarding this.

Yes, that is perfectly ok.

I don't understand what you are saying...IKK is for Aeroplan rewards.

Basically, you are saying that if you get your upgrade confirmed, can you change your flight date with penalty + fare difference, and then upgrade the new flight.

Why not?

Kinda makes you wish you bought a latitude ticket, eh?

Perhaps instead of stating IKK I should have indicated upgraded in the 4 (E) or 7 (SE) window via R class. Either way what I thought was perfectly fine indeed is.

That would have been more clear... IKK has nothing to do with upgrades so it probably confused a few people (like me!) :)

as did the reference to class of service fee...

What about the same day?

If you elect to 'upgrade with cert' during OLCI, depending on availability the system may give you the opportunity to standby for earlier flight (or perhaps to confirm for another flight, I can't recall).
It may do the same for LMU - I've never tried it.

You go to the airport and when the GA calls you up to exchange your old boarding pass for the new one, you say you've decided not to use the cert. Are you downgraded to Y on the earlier flight or downgraded to Y on the original later flight? (You check ahead of time to be sure that neither flight is oversold in Y)

[of course, maybe you never had the cert in the first place...]

I believe if the OLCI lets you standby for an earlier flight you'd need to pay the same day change fee at the airport. Either way if you're upgraded on a cert your sameday change fees are still covered by your original booking class. Same goes for changing flights, if there is no J you'd be in Y - not sure if being confirmed in J would bump you back on the waitlist or let you skip it.

Not in my experience (n=4 or 5) Once you have upgraded to J, the system seems to think you are in J, so it allows the standby/same day change at no cost. So just to be more clear (I was trying to avoid clarity), my question is not whether this would put you on the waitlist, but rather, is this effectively a loophole that may allow one to avoid the same day change fee.